If a bankruptcy is filed and you had $ or BTC at bitfloor, you should be included on the list of creditors, and you'll get periodic mailings about the progress of the matter.
Now we are getting to the really interesting stuff. If BitFloor does not have any information on how to contact you, how will you get periodic mailings?
If some other legal action is filed, there's a pretty good chance you'll be included as a party, which would mean you'll get copies of filings,
See my question above.
The best thing to do is to make sure that BitFloor does have a mailing address for you - then there's no excuse for not giving you notice of proceedings. It's possible that a judge would order them to send notice via E-mail; but it's also possible that won't happen. The standard in the legal community is to communicate via postal mail, and the assumption is that everyone's got a postal address where they can be notified of things.
People who don't want to participate in that system don't have to, but they'll also need to get their news second-hand.